Reducing wireless interference from a wired digital interface

ABSTRACT

Circuits and systems may be operable to provide improved wireless networking performance in the presence of a high speed wired interface. Filter circuits may be applied to wired interface leads to suppress frequency content that may interfere with wireless home networking. High speed digital wired interface systems on a chip may similarly be altered to suppress interfering frequency content before it leaves the chip. Systems with reduced radiated energy from wired interface circuits in frequencies of interest to wireless networking have improved wireless range and throughput characteristics.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 15/889,465,filed on Feb. 6, 2018, the contents of which are incorporated herein.

TECHNICAL FIELD

This disclosure relates to reducing the interference generated by wiredinterfaces on wireless interfaces.

BACKGROUND

Wireless networking has become increasingly popular in a wide range ofhome electronic devices. Wireless connections such as IEEE 802.11ac®generally have enough bandwidth and robustness to pass video signals,such as between a home gateway and a set top box. Televisions alsocommonly have wireless interfaces to receive video content and othercontent. Wireless receiver sensitivity is an important productparameter, so a device supporting wireless networking may have one ormore antennas incorporated into its enclosure. Also, the receivercircuitry itself may be sensitive to noise received through power orground connections. Examples of wireless networking technologies includeIEEE 802.11 (also known as Wi-Fi), Bluetooth, and Zigbee among manyothers. The most popular wireless interface devices operate within theIndustrial, Scientific and Medical (ISM) frequency bands and theUnlicensed National Information Infrastructure (UNII) bands. The ISMbands typically used in the United States are 2.4 to 2.5 GHz and 5.725to 5.875 GHz. The UNII bands expand the 5 GHz ISM band to 5.15 GHZ to5.925 GHz. These frequencies are exemplary; frequency allocations arechanged by the FCC periodically and new allocations, such as theCitizens Broadband Radio Service (CBRS), are often added.

In addition to the wireless interfaces used on modern consumerelectronics, high speed digital wired interfaces are also common. Anexample high speed digital wired interface is High Definition MultimediaInterface® (HDMI), a very common and popular home networking wiredinterface for video delivery. An HDMI interface typically connects a settop box or other video source to a display device such as a televisionor video projector. An HDMI transmit interface is sourced from anintegrated circuit providing an assortment of signal and clock traces toan external connector. The external HDMI connector receives the signalsfrom the integrated circuit and deploys them in a standardized connectorassembly. HDMI also specifies a receive interface on devices such asvideo displays or televisions. In an HDMI receive configuration, theexternal HDMI connector assembly receives signals and deploys the signaland clock leads onto traces on the motherboard. Those HDMI traces run toan integrated circuit that receives and processes them. Generally,though the descriptions use the example embodiment of an HDMI sourcedevice, the invention is equally applicable to an HDMI sink device. Whenan HDMI source device is first connected to an HDMI sink device, theyexchange configuration parameters, if needed.

The frequencies of signals, including clock signals, on many wiredinterfaces overlap with the frequencies used by wireless interfaces. Forexample, while the frequency content of HDMI signals does vary dependingupon the specific settings of an HDMI interface, such as resolution andframe rate, HDMI signals consistently have frequency content thatoverlaps with that of typical wireless interfaces. When bothtechnologies are deployed in a single device, energy from HDMI signalsmay be radiated as the HDMI traces run between the integrated circuitand the HDMI connector.

Additionally, some HDMI cables have low levels of shielding, alsoallowing HDMI signals to radiate from the cable outside of the HDMIconnector on the STB. If this radiated energy is absorbed by wirelessantennas or circuitry, then that energy contributes noise to thewireless receiver, resulting in decreased wireless range and throughput.This decreased performance is detrimental to the usefulness of theproduct. Consumer electronic devices, such as set top boxes are underpressure to be as small and compact as possible. Display devices areunder similar pressure to be thin and minimize externally visibleconnections. This decrease in size often forces the wired interfaces andthe wireless interfaces closer together, which tends to increaseradiative coupling between wired interface internal traces and externalwiring with the wireless receiver assembly.

While HDMI has been discussed as an exemplary high speed digital wiredinterface, many other similar technologies exist. Some other examplesare Multimedia over Coax Alliance (MoCA), Ethernet, and Universal SerialBus (USB).

Therefore, a need exists for improved methods and systems to reducewired interface interference with wireless interfaces in electronicdevices.

SUMMARY OF INVENTION

Methods and apparatus are presented to reduce interference from wiredinterfaces with wireless interfaces in electronic devices. Inembodiments, a communication apparatus containing a wired interfaceusing a first frequency band and a wireless interface using a secondfrequency band is presented with a wired interface signal unitconfigured to produce a wired interface output signal having energywithin the first frequency band, a filter configured to attenuate thewired interface output signal and an output configured to provide theattenuated wired interface output signal to an external device, suchthat the filter attenuates portions of the wired interface output signalwhich have energy in the second frequency band. In embodiments, thewired interface may be an HDMI interface, a MoCA interface, an Ethernetinterface or a USB interface. In embodiments, the filter may be abandstop filter having a stop band which attenuates portions of thewired interface output signal which have a frequency between 2.4 GHz and2.5 GHz, or between 3.55 GHz and 3.7 GHz or between 5 GHz and 6 GHz. Inother embodiments, the filter may be a lowpass filter having a passbandbelow 2.4 GHz, or below 3.55 GHz, or below 5.15 GHz.

A method of reducing interference with a wireless communicationinterface from a wired interface while producing wired interface outputsignals is presented such that the energy content of the wired interfaceoutput signals in at least one frequency range used by the wirelesscommunication interface is selectively reduced. In embodiments, thewired interface may be an HDMI interface, a MoCA interface, an Ethernetinterface or a USB interface. In embodiments, different frequency rangesmay be used. For example, the frequency range may include a portion ofthe band between 2.4 GHz and 2.5 GHz, or a portion of the band between3.55 GHz and 3.7 GHz, or a portion of the band between 5 GHz and 6 GHz.In embodiments, the reduction of energy may be produced by using adigital filter before the signals of the wired interface are sent tooutput leads. In other embodiments, the reduction of energy may beproduced by using an internal analog filter before the signals are sentto output leads. In embodiments, a selectable control may be used toenable or disable the reduction of energy, additionally a selectablecontrol may provide the ability to select the frequency range to beaffected.

In other embodiments, a non-transitory computer readable media may haveinstructions operable to cause one or more processors to receive aselection of a frequency band to be suppressed in a wired interface, tostore the configuration data recording the selection, to select a filterappropriate to suppress the selected frequency band, and to produce afiltered wired interface signal, such that the filter suppressesfrequency components of the wired interface signals which correspondwith the selected frequency band.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example set top box possessingwireless networking and an HDMI port.

FIG. 2a is a graph illustrating the frequency components of an exampleunaltered HDMI signal.

FIG. 2b is a graph of an eye diagram for an example unaltered HDMIsignal.

FIG. 3 is a block diagram illustrating an example set top box possessingwireless networking, and an HDMI port and an HDMI filter circuit.

FIG. 4a is a graph illustrating a notch filter with reference to an HDMIsignal.

FIG. 4b is a graph of an eye diagram for the HDMI signal after passingthrough the notch filter of 4 a.

FIG. 5a is a graph illustrating a low pass filter with reference to anHDMI signal.

FIG. 5b is a graph of an eye diagram for the HDMI signal after passingthrough the low pass filter of 5 a.

FIG. 6 is a block diagram illustrating an example hardware platformoperable with reduced wireless interference from an improved HDMIintegrated circuit.

FIG. 7 is a block diagram of a process flow for a component's filterinitialization.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

It is desirable to provide improved methods and systems for improvedwireless performance in the presence of a high speed digital wiredinterface.

FIG. 1 is a block diagram illustrating an example prior art set top box(STB) 101 with a wireless interface and an HDMI interface connected to adisplay device 110. While other wired interfaces are equally possible,this implementation uses an HDMI interface as an exemplary high speeddigital wired interface. STB 101 may include a wireless interface 102, aprocessor 103, a memory 105, and an HDMI integrated circuit (IC) 106with an HDMI connector 107. Each of the components 102, 103, 105, and106 may, for example, be interconnected using a system bus 104.Processor 103 may be capable of processing instructions for executionwithin STB 101 including instructions for video processing. In oneimplementation, processor 103 may be a single-threaded processor. Inanother implementation, processor 103 may be a multi-threaded processor.Processor 103 may be capable of processing instructions stored in memory105. Processor 103 may be capable of processing video received fromwireless interface 102 for delivery to display device 110 through HDMIIC 106.

The content for an HDMI interface may be provided from a variety ofsources. As an example, wireless interface 102 utilizes antenna 112 toreceive wireless signals carrying information destined for STB 101.Information delivered over wireless interface 102 is provided toprocessor 103 over bus 104 for processing into a form suitable fordelivery over HDMI interface 105 to display device 110. Videoinformation, for example, is commonly delivered in a compressed formwhich must be decompressed for an HDMI interface.

Memory 105 may store information within STB 101 for the wirelessinterface 102 as well as processor 103. In one implementation, memory105 may be a computer-readable medium. In one implementation, memory 105may be a volatile memory unit. In another implementation, memory 105 maybe a non-volatile memory unit. In yet another implementation, memory 105could be a combination of both volatile and non-volatile memories.

Processor 103 provides the processed video information to HDMIintegrated circuit (IC) 106 using bus 104. While HDMI IC 106 is shown asa separate block from processor 103, in other embodiments, processor 103and HDMI IC 106 may be component parts of a single system on a chip.Such a system on a chip may include other functionality not relevant tothis invention.

HDMI IC 106 receives processed video information from processor 103.HDMI IC 106 formats the information to comply with at least one of theHDMI output interface specifications. The HDMI signals produced by HDMIIC 106 are configured by initial interactions between STB 101 anddisplay device 110 during the HDMI initialization sequence. For example,an HDMI Type A interface requires 3 differential data pairs in additionto a differential clock pair and other support signals, such as a hotswap detection lead. HDMI IC 106 provides HDMI signals to HDMI interface107.

HDMI interface 107 is a standardized connector assembly that allows acable to be connected to an external device, such as a display for STB101. HDMI interface 107 is connected to HDMI IC 106 by a bus made up ofmultiple traces with signal and clock leads.

FIG. 2a is an illustration of a typical 1080P60 HDMI data signal'sfrequency components simulated passing through an all-pass filterdenoted by the broad line 210. HDMI signal 201 has frequency componentsthat extend up through 10 GHz. High speed digital interface signalscommonly have high frequency content that may have some periodictendencies, as HDMI signal 201 does in the FIG. 2a . Line 210 indicatesthe all-pass filter applied to the signal. Wireless home networking forvideo signals is often in the UNII band around 5 GHz. This figure showsHDMI signal 201 has substantial energy in that frequency range. Otherbands of potential interest for wireless home networking include the ISMband around 2.4 GHz and the Citizens Broadband Radio Service (CBRS) bandaround 3.5 GHz. Any of these bands also may be exposed to energy from anHDMI signal.

FIG. 2b is an illustration of the same simulated HDMI signal, nowdenoted HDMI signal 202, in the time domain, also known as an eyediagram. The HDMI specifications do not specify the energy required inthe frequency bands illustrated in FIG. 2a , but instead placerequirements upon the eye diagram shown in FIG. 2b . The HDMIspecification requirements are embodied in polygon 220. To be compliantwith HDMI specifications, eye diagram 202 must not impinge on polygon220. Note that while the graphs used in this description are from asimulation of a 1080P60 HDMI interface, other HDMI modes such as 4KP60have similar characteristics.

FIG. 3 illustrates a block diagram of an improved STB 301 with reducedexposure to wireless interference from HDMI signals connected to adisplay device 310. While other wired interfaces are equally possible,this implementation uses an HDMI interface as an exemplary wiredinterface.

In STB 301, the wireless interface 302 provides network connectivity forSTB 301 to receive multimedia content from a wireless home network. Asdiscussed earlier, in embodiments, wireless interface 302 may operate ina single wireless band, such as the 5 GHz UNIT band. Other embodimentsmay utilize other unlicensed or licensed bands with wireless interface302. While this diagram illustrates a system with a single antenna, inembodiments there may be several antennas for a single radio band. Also,STB 301 may support more than one frequency band with different antennasfor each band.

The content for an HDMI interface may be provided from a variety ofsources. In this example implementation, wireless interface 302 utilizesantenna 312 to receive wireless signals carrying information destinedfor STB 301. In embodiments, information delivered over wirelessinterface 302 may be provided to processor 303 for processing into aform suitable for delivery over HDMI interface 308 to display device310. Processor 303 provides the processed video information to HDMIintegrated circuit (IC) 306. While in this embodiment HDMI IC is shownas a separate block from processor 303, in other embodiments, processor303 and HDMI IC 306 may be component parts of a single system on a chip.Such a system on a chip may include other functionality not relevant tothis invention.

In embodiments, HDMI IC 306 receives processed video information fromprocessor 303. HDMI IC 306 may format the information to comply with atleast one of the HDMI output interface specifications. For example, anHDMI Type A interface requires 3 differential data pairs in addition toa differential clock pair and other support signals, such as a hot swapdetection lead. HDMI IC 306 provides HDMI signals to HDMI filter circuit307.

In embodiments, HDMI filter circuit 307 suppresses the energy of theHDMI compliant signals in the band or bands likely to cause interferencewith wireless interface 302. In other embodiments, the functionality ofHDMI filter circuit 307 could be included in an HDMI companion chip,such as the Texas Instruments TPD12S016. A companion chip in the priorart provides output protection from static discharge or other adverseconditions for HDMI ICs, such as HDMI IC 306.

In embodiments, after the HDMI filter circuit 307, the HDMI traces,which may include signal data and clock signals, are continued to HDMIinterface 308. HDMI interface 308 is a standardized connector assemblythat allows a cable to be connected to display device 310.

Different forms are possible for HDMI filter circuit 307 that wouldstill be in accordance with this invention. When describing a filter, itis common to use the term passband for the frequencies allowed to passthrough without significant attenuation and the term stopband for thosefrequencies attenuated significantly by the filter. In embodiments, HDMIfilter circuit 307 could take the form of a notch or bandstop filterthat suppresses signal energy only a single block or band offrequencies.

FIG. 4a illustrates an example notch filter embodiment with the notchcentered on the ISM UNIT band from 5.15 GHz to 5.85 GHz. HDMI signal 401is shown with notch filter 410. The attenuated portion of HDMI signal401 is shown as completely suppressed, while in a realistic embodimentsome energy would typically remain. Eye diagram 402 in FIG. 4b shows atime domain representation of HDMI signal 401 that has passed throughfilter 410 of FIG. 4a . While the removal of that band of highfrequencies does affect the eye diagram, eye diagram 402 is stillcompliant with HDMI requirement polygon 420.

A notch circuit is well known to be more challenging and costly toproduce than a low pass filter. In embodiments, HDMI filter circuit 307could alternatively take the form of a low pass filter that allows allfrequencies below the wireless band of interest to pass, but attenuatesall frequencies above the beginning of that band.

FIG. 5a illustrates one example embodiment with a low pass filter thatallows frequencies below the ISM band which begins at 2.4 GHz to passwith minimal attenuation but attenuates frequencies above 2.4 GHz. HDMIsignal 501 is attenuated by low pass filter 510 in those higherfrequencies. FIG. 5b shows the eye diagram of HDMI signal 501 that haspassed through low pass filter 510. The exemplary eye diagram 502 ofHDMI signal 501 is degraded from the unfiltered eye diagram example fromFIG. 2b , but for uses where eye diagram 502 avoids overlap with polygon520, this signal is advantageous since it also eliminates frequenciesthat might cause wireless interference. A person of skill in the art ofRF filters would understand that a real filter has slope from thepassband to the stop band. A realizable filter might have a knee at 2.3GHz and a slope of 20 dB per decade. Other filters are possible inembodiments and would be recognized as providing the same signalsuppression in one or more of the available wireless bands. While anHDMI wired interface is used as an example implementation, other digitalwired interfaces may similarly allow filtering of their signal spectrato reduce wireless interference without rendering the signalsnoncompliant with their respective standards.

FIG. 6 is a block diagram of an alternative embodiment STB 601 operableto reduce the wireless interference of an HDMI interface connected to adisplay device 610. While other wired interfaces are equally possible,this implementation uses an HDMI interface as an exemplary wiredinterface.

In embodiments, processor 603 may be capable of processing instructionsfor execution within STB 601 including instructions for videoprocessing. Processor 603 may be capable of processing video receivedfrom wireless interface 602 for delivery to an external display throughHDMI+Filter IC 606.

Information delivered over wireless interface 602 is provided toprocessor 603 over bus 605 for processing into a form suitable fordelivery over HDMI interface 607 to display device 610.

Memory 604 may store configuration information within STB 601 for thewireless interface 602 as well as processor 603.

Processor 603 provides the processed video information to HDMI+Filter IC606. While HDMI IC 606 is shown as a separate block from video processor603, in other embodiments, processor 603 and HDMI IC 606 may becomponent parts of a single system on a chip. Such a system on a chipmay include other functionality not relevant to this invention.

HDMI+Filter IC 606 receives processed video information from processor603. HDMI+Filter IC 606 is capable of providing video and audioinformation to display device 610 via an HDMI-compliant connector. Insome embodiments, to reduce interference with wireless interface 602,HDMI+Filter IC 606 incorporates additional signal processing to suppressor attenuate portions of the HDMI signals that would otherwise interferewith the wireless interface 602. In embodiments, the signal processingmay result in the elimination of signal energy in a band of frequenciessimilar to the implementation of an external notch filter. In otherembodiments, the signal processing may result in the removal orattenuation of signal energy in frequencies above a certain frequency,similar to the implementation of an external low pass filter. Theselection of which embodiments are enacted by HDMI+Filter IC 606 may beconfigured by processor 603. Processor 603 may select a filterembodiment based on an internal configuration, such as that of wirelessinterface 602, or the selection may be made based upon informationreceived from the connected display device 610. An example process forthat decision is discussed with FIG. 7. Other embodiments to selectivelyattenuate the signal energy in frequencies within the larger outputspectra may occur to those skilled in the art of digital signalprocessing. In embodiments, HDMI+Filter IC 606 may comprise a singlechip implementation. In other implementations, the functionality ofHDMI+Filter IC 606 may be part of a multi-chip module. In still otherimplementations, the functionality of HDMI+Filter IC 606 may beintegrated within processor 603.

HDMI interface 607 is a standardized connector assembly that allows acable to be connected to display device 610. HDMI interface 607 isconnected to HDMI+Filter IC 606 by a bus made up of multiple tracescomprising signal and clock leads.

Turning to FIG. 7, an example process is presented allowing a componentwith a programmable filter, such as HDMI+Filter IC 606, to be configuredfor operation. In step 701, the IC component enters a filterinitialization mode. In embodiments, this mode may be triggered by theapplication of power to the IC or by a configuration trigger from aninternal or external source. As an example, if display device 610 isturned on, the initialization of the HDMI link to HDMI interface 607 andHDMI+Filter IC 606 could trigger a filter initialization.

In step 702, the component determines if a filter has been selected by aconnected device. Not all embodiments may support filter selection by aconnected device. If an embodiment supports filter selection by aconnected device, then the component may determine that a connecteddevice has selected a filter to be instantiated by the component. Inembodiments, the component may support a limited set of filters foractivation. For example, a component may support only a low pass filterwith a cut off of 5 GHz that can be activated or not. Alternatively, acomponent might support a programmable notch filter whose bandwidth andcenter frequency were selectable between 2.4 GHz and 5.5 GHz. Inembodiments, the determination that a connected device has selected afilter may be made based upon configuration settings communicated overthe wired link during initialization. Alternatively, another wired orwireless link may be used by the connected device if the wired link isnot available for communication until initialization is complete. If thecomponent determines that a filter has been selected by the connecteddevice, then the process continues to step 704. It should be noted thatin some embodiments, a connected device may be able to select anall-pass filter which is the effective selection of no filter on theoutput signals. If the component determines that the connected devicehas not selected a filter, then the process continues to step 703.

In step 703, the component determines if internal configuration dataindicates that a filter has been selected. In embodiments, the internalconfiguration data may be provided to the component at initialization byan external management system. In other embodiments, the component mayhave a stored configuration that instructs the component as to whichfilter, if any to instantiate. If a filter is required by internalconfiguration data, the process continues to step 704. If not, theprocess continues to step 705.

In step 704, the component instantiates the selected filter. Inembodiments, the component may make use of various well-known digitalsignal processing techniques to provide the requested filter on theappropriate signals, including for example software-defined filters.Many techniques are known to those skilled in the art of digital signalprocessing to suppress energy content of a signal in selected frequencybands, which is the essence of a filter.

In step 705, the component does not instantiate a filter on the outgoingsignals. In embodiments, the lack of filtering may be implemented by anall-pass filter. In other embodiments, the component may simply notactivate any additional filtering of the appropriate signals.

Those skilled in the art will appreciate that the invention describedherein reduces the interference of wired interfaces with wirelessinterfaces. The embodiments presented illustrate that the invention maybe implemented through many different embodiments in order to reduce,for example, interference from HDMI wired interfaces with wirelessinterfaces by reducing the energy of the HDMI signal in frequency bandsalso used by wireless interfaces. Typical high speed wired interfacedesigns seek to optimize an eye pattern without regard to its inherentfrequency components. Those frequency components are typically onlyevaluated against broad spectrum radiated emission standards, such asFCC Part 15. The general radiated emissions standards have no additionalrestrictions for radiation in the unlicensed ISM and UNIT bands used forwireless interfaces. The embodiments presented use controlleddegradation of the eye pattern resulting from suppression of specificfrequency bands to both provide a compliant wired signal as well asreduced wireless interference.

The subject matter of this disclosure, and components thereof, may berealized by instructions that upon execution cause one or moreprocessing devices to carry out the processes and functions describedabove. Such instructions may, for example, comprise interpretedinstructions, such as script instructions, e.g., JavaScript orECMAScript instructions, or executable code, or other instructionsstored in a computer readable medium.

Implementations of the subject matter and the functional operationsdescribed in this specification may be provided in digital electroniccircuitry, or in computer software, firmware, or hardware, including thestructures disclosed in this specification and their structuralequivalents, or in combinations of one or more of them. Embodiments ofthe subject matter described in this specification may be implemented asone or more computer program products, i.e., one or more modules ofcomputer program instructions encoded on a tangible program carrier forexecution by, or to control the operation of, data processing apparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) may be written in any form of programminglanguage, including compiled or interpreted languages, or declarative orprocedural languages, and it may be deployed in any form, including as astand-alone program or as a module, component, subroutine, or other unitsuitable for use in a computing environment. A computer program does notnecessarily correspond to a file in a file system. A program may bestored in a portion of a file that holds other programs or data (e.g.,one or more scripts stored in a markup language document), in a singlefile dedicated to the program in question, or in multiple coordinatedfiles (e.g., files that store one or more modules, sub programs, orportions of code). A computer program may be deployed to be executed onone computer or on multiple computers that are located at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

The processes and logic flows described in this specification areperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output thereby tying the process to a particular machine(e.g., a machine programmed to perform the processes described herein).The processes and logic flows may also be performed by, and apparatusmay also be implemented as special purpose logic circuitry, e.g., anFPGA (field programmable gate array) or an ASIC (application specificintegrated circuit).

Computer readable media suitable for storing computer programinstructions and data include all forms of non-volatile memory, mediaand memory devices, including by way of example semiconductor memorydevices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks(e.g., internal hard disks or removable disks); magneto optical disks;and CD ROM and DVD ROM disks. The processor and the memory may besupplemented by, or incorporated in, special purpose logic circuitry.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinvention or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particularinventions. Certain features that are described in this specification inthe context of separate embodiments may also be implemented incombination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment may also beimplemented in multiple embodiments separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination may in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, the separation of various system components in theembodiments described above should not be understood as requiring suchseparation in all embodiments, and it should be understood that thedescribed program components and systems may generally be integratedtogether in a single software product or packaged into multiple softwareproducts.

Particular embodiments of the subject matter described in thisspecification have been described. Other embodiments are within thescope of the following claims. For example, the actions recited in theclaims may be performed in a different order and still achieve desirableresults, unless expressly noted otherwise. As one example, though asingle wireless interface and a single HDMI interface are illustrated inthe examples, the principles of the invention are equally applicable todevice with multiple wireless interfaces or multiple HDMI interfaces.Although, the examples given illustrate the improvements possible in the5 GHz UNIT band, the invention is equally applicable to wirelessinterfaces using the 2.4 GHz ISM band or to devices that have more thanone wireless interface. In some implementations, multitasking andparallel processing may be advantageous.

I claim:
 1. A communication apparatus containing a wired interface usinga first frequency band and a wireless interface using a second frequencyband, the communication apparatus comprising: a wired interface signalunit configured to produce a wired interface output signal having energywithin the first frequency band; a wireless interface signal unitconfigured to communicate using the second frequency band; a filterselectively configured to attenuate the wired interface output signal; aprocessor operatively coupled to the filter and a memory withconfiguration data; and an output configured to provide the attenuatedwired interface output signal to an external device, wherein theprocessor instructs the filter to attenuate portions of the wiredinterface output signal which have energy in the second frequency bandif the configuration data indicates that the second frequency band is inuse by the wireless interface.
 2. The circuit of claim 1, wherein thewired interface is one of an HDMI interface, a MoCA interface, anEthernet interface or a USB interface.
 3. The circuit of claim 1,wherein: the filter is a bandstop filter having a stop band whichattenuates portions of the wired interface output signal which have afrequency between 2.4 GHz and 2.5 GHz.
 4. The circuit of claim 1,wherein: the filter is a bandstop filter having a stop band whichattenuates portions of the wired interface output signal which have afrequency between 3.55 GHz and 3.7 GHz.
 5. The circuit of claim 1,wherein: the filter is a bandstop filter having a stop band whichattenuates portions of the wired interface output signal which have afrequency between 5 GHz and 6 GHz.
 6. The circuit of claim 1, wherein:the filter is a lowpass filter having a passband below 2.4 GHz.
 7. Thecircuit of claim 1, wherein: the filter is a lowpass filter having apassband below 3.55 GHz.
 8. The circuit of claim 1, wherein; the filteris a lowpass filter having a passband below 5.15 GHz.